Modal verbs

1. Prohibition

1.1. musn't

1.2. to be prohibitted

2. Posibility

2.1. migth

2.2. may

2.3. could

3. Ability

3.1. can

3.2. be able to

4. Permisson

4.1. can

4.2. be allowed to

4.3. may

5. Obligation

5.1. must

5.2. have to

5.3. be obliged to

6. Necessity

6.1. needn't

6.2. need

7. Advice

7.1. should

7.2. ought to

8. Absense of obligation

8.1. Needn't

8.2. Don't have to